Suspension band of a venetian blind or the like

ABSTRACT

A VENETIAL BLINK WITH STRUCTURE FOR READILY REPLACING THE SUSPENSION TAPES OR BANDS INCLUDING A WIRE HOOP OR LATCH MEMBER MOUNTED IN A SLOT IN THE WINDING DRUM AND RETRACTABLE AGAINST A SPRING WHICH NORMALLY BIASES IT TO TAPE RETAINING POSITION.

United States Patent Inventor Gunther Breymann Emmerich, Germany Appl.No. 823,897 Filed May 12,1969 Patented June 28, 1971 Assignee JustinHuppe Oldenburg, Germany Priority May 21, 1968 Germany 62765 ISUSPENSION BAND OF A VENETIAN BLIND OR THE LIKE 8 Claims, 4 DrawingFigs.

US. Cl... 160/178 Int. Cl E06b 9/384 [50] Field of Search 160/166- [56]References Cited UNITED STATES PATENTS 1,287,817 12/1918 Anshen 24/2391,389,500 8/1921 Goodrich et al,. 242/74.1X 2,229,221 1/1941 Pratt 160/171X 2,482,625 9/1949 Kunkel 24/239X 2,948,487 8/1960 Locklin 242/742Primary Examiner- Peter M. Caun Attorney-Olson, Trexler, Wolters &Bushnell ABSTRACT: A venetian blind with structure for readily replacingthe suspension tapes or bands including a wire hoop or latch membermounted in a slot in the winding drum and retractable against a springwhich normally biases it to tape retaining position.

SUSPENSION BAND OF A VENETIAN BLIND OR THE LIKE The subject matter ofthe present invention is an attachment device for the pullup band of avenetian blind or a similar type of shutter made up of slats. The deviceconsists of a wire hoop which is axially shiftable in the hub of thewinding drum and passes through a radial recess of said hub or boss.This wire hoop may be inserted across the terminal loop of the pullup orsuspension band when the loop is introduced into said recess.

Venetian blinds commonly comprise a series of slats supported by apullup device comprising a band consisting of steel or of a textilefabric, which band as the venetian blind is pulled up, becomes wound insuperimposed layers upon a winding drum. It is known in the prior art toanchor the terminal pullup or suspension band at the hub of the windingdrum in the manner outlined above. The wire hoop which is actually amore or less straight wire peg, it shiftable in an axial, longitudinalbore or slit in the hub of the drum. In order to introduce or remove theterminal loop of the pullup band this hoop is laterally pulled out ofthe drum for such a distance that its oppositely located free end iscompletely retracted from the recess inside the hub, so that the loopmay be introduced into or pulled out of this recess.

However the reinsertion of the hoop in this known construction is besetwith difficulties because the hoop is no longer reliably guided at thisside of the recess inside the hub which it was completely pulled out. Ifpullup or suspension bands have been damaged or worn out their exchangemust take place when the venetian blinds'are hanging in front of thewindow, where the winding drums of course are not easily accessible.Therefore the assembly work with this known construction is rathercumbersome.

According to the present invention the insertion or replacement of theterminal loop of a pullup band is simplified in that a spring pressesthe wire loop into its engagement position in which it will pass throughthe loop. The wire hoop is shiftable against the force ofthe spring intoa ready position which releases the loop. In this position the hoop isguided across essentially its full length in the winding drum. Wheninserting the terminal loop of a pullup band into the new attachmentdevice one does not have to pay much attention to the wire hoop. Allthat is necessary is to watch that the loop is placed in its correctposition in the recess of the hub. Once this has been accomplished, onereleases the hoop, and the spring then will shift the hoop automaticallyinto its position of engagement.

In order to maintain the guidance of the wire hoop in the hub of thedrum it is advantageous that the wire hoop in its positions ofengagement and of readiness is located completely inside the windingdrum. Such an arrangement is possible especially when, as is done in thepresent invention, the winding drum is combined in one constructionalunit with the friction drums for the loops of the supporting and turningmeans which are placed over the winding drum.

The wire hoop preferably has more or less the shape of the letter U, butwith legs of different lengths, whereby the shorter leg serves for theaccommodation of the loop and in the ready position will be locatedoutside the recess, whereas the longer leg serves for theguidance andfor the shifting of the wire hoop. In this manner the wire hoop willalways be on both sides of the recess, even then when in the readyposition the portion of the wire hoop which serves for engaging into theloop ofthe pullup band, has been pushed out of the recess.

The free end of the long leg of the wire hoop serves as a manuallyengageable part for retracting the hoop. In order best to accomplishthis an axial slit is provided in the winding drum passing radially allthe way to the outside. This slit is at least partially open at thefrontal side of the winding drum adjacent to the free end of the longleg of the wire hoop.

n the attached sheet of drawings a typical example is presented oftheinvention, wherein:

FIG. 1 is a plan view, partially cut away, of the winding drum which isequipped with the attachment device according to the invention, with thepullup band inserted, whereby the wire hoop is in its engagementposition;

FIG. 2 is a drawing similar to FIG. 1, where the wire hoop is in itsready position;

FIG. 3 is a section along line 1-11-lIIofFlG. 1; and FIG.

FIG. 4 is a plan view correspond-ing to FIG 1 wherein nothing has beencut away; FIG. 4 is being turned with respect to FIG. 1 by i.e. thewinding drum has been turned around its axis of rotation by 90 The drumblock 1 is manufactured as a one-piece synthetic or plastic molding,combining the winding drum 2- for the pullup band 3 with two similarfriction drums 4 and 5 respectively located at the right and at the leftof the'winding drum 2; these friction drums being provided for thesupporting and turning (or tilting) bands of the venetian blind. At oneside the drum block continues as a trunnion 6 equipped with stepwis'elystaggered collars or flanges for the accommodation of bearings. A

central bore 7 passes through the drum block from one side to the otherand receives the driving axle (not shown) of the venetian blinds for, asa rule, several more or lesssimilar drum blocks 1.

An axial blind bore 8 extends in parallel to the bore 7 through the hub9 of the winding drum 2 and also through the hubs of the friction drums4 and 5. In the regionof this bore 8, which lies eccentrically to thecentral bore 7, the hub 9 of the winding drum 2 is provided with arecess 10 which extends all the way to the central bore 7, the recess 10in effect widens the bore 8 in the region of the winding drum 2.

An axial slit 11 is provided in the region of the friction drum 5 andextends from the bore 8 radially outwardly and passes completely throughthe hub of thedrum 5 (see FIGS. 1 and 4) with the exception of theinternal frontal wall thereof, which forms simultaneously the onefrontal wall of the winding drum 2. Finally another slit 12 is providedin the region of the friction drum 5 passing axially through all of thehub, which slit 12 starts out tangentially from the bore 8 and goesvertically to the slit 11, as may be recognized from FIG. 3.

Into the unilaterally closed section of the bore 8, which is located inthe hub region of the friction drum 4, is inserted a coil spring 13which at the one end rests against the closed end of the bore 8. Theother end of the spring pressesag'ainst the short, curved crossbar orbight 14, of a wire hoop or retainer 15 which essentially is bent likethe letter U and which is disposed in the bore 8. The two legs of the Uhave different lengths. The long leg 16 of the hoop 15 is offset at itsfree end at 17. This offset end 17 is guided in the slit 1] and servesformanually engaging the wire hoop 15 either radially in thecircumferential region of the hub of the friction drum 5, or axiallyacross the frontside of the opening 18 of the slit 11 in the externalfrontal wall of the drum 5. The opening 18 thereby is dimensioned suchthat the wire hoop 15 is not pressed out of the drum by the spring 13,but is capable of being inserted by application of an additional force.The long leg 16 of the wire hoop 15 is bent laterally near its free endso as to form a motion-limiting stop 19, in a direction which isstaggered by 90 to the offset end 17. The stop- 19 which limits themotion, is guided inside the slit 12 of the hub of the friction drum 5.

The short leg 20 of the wire hoop l5 lies radially outwardly withrespect to the long leg 16. In FIG. 1 the engagement position is shownwherein the short leg 20 passes through the terminal loop 21 of thepullup band 3. When the wire hoop I5 is shifted axially into theposition shown in FIG. 2, the short leg 20 of the wire hoop 15 willleave the loop 21 completely and release this loop. (In FIG. 2 thepullup band 3 with the loop 21 has been drawn as loose.) If the wirehoop l5, which can be retained in the ready position shown in FIG. 2only under the application of a tool (not shown), is subsequentlyreleased, then the wire hoop 15 under the force of the spring 13 willreturn again into the engagement position which is shown in FIG. I. Ifthis is done with the loop 21 of the pullup band 3 maintained in thepath of motion of the short leg 20, anchoring of the pullup band takesplace in the manner described above.

Iclaim:

1. An attachment device for the suspension band of a Venetian blind orthe like having a winding drum for the band, said drum having a radialrecess therein, said device comprising a latch member receivedthroughout its length in said recess and a spring in said recess biasingsaid latch member axially of said drum into position for retaining asuspension band on said drum, said latch member while remaining entirelywithin said recess being manually axially movable against said spring toa releasing position for removal or installation of a band.

2. A device as set forth in claim 1 wherein said latch member is a wirehoop.

3. A device as set forth in claim 2 wherein the wire hoop issubstantially U-shaped, having a pair of legs of different lengths, theshorter legserving to engage a band endpiece and the longer leg servingtoguide and to shift said wire hoop.

4. A device as setforth in claim 3 wherein the spring is a helicalspring and abuts the bight interconnecting the legs of the wire hoop.

5. A device as set forth in claim 3 wherein the longer leg has a radialoffset received in a radial slit extension of said recess.

6. A device as set forth in claim 3 wherein the longer leg of the hoophas a lateral offset forming a motion limiting stop.

7. A device as set forth in claim 3 wherein said band endpiece ispositioned adjacent a portion of said recess and wherein said longer legis of sufficient length to extend across the portion of said recessadjacent said band endpiece when said latch member is in its releasingposition whereby to guide said latch member to its retaining position.

8. A device for attaching a suspension band of a venetian blind or thelike to the hub portion of a winding drum having sidewall portionsadjacent said hub portion and a recess extending through said hub andsidewall portions, said device comprising a latch member receivedthroughout its length in said recess and a spring in said recess biasingsaid latch member axially of said drum into position for retaining saidsuspension band on said drum, said latch member being manually axiallymovable against said spring to the releasing position for removal orinstallation of said band, said latch member including a substantiallyU-shaped wire hoop having a pair of legs of different lengths, theshorter leg serving to engage a band endpiece positioned on said hubportion and longer leg being of sufficient length so as to extendthrough the portion of said recess defined by said hub portion when Isaid latch member is in either of said positions.

